No. There's no way to implement a feature like this without help from the backends, and I'm only going to do it in the cairo backend as that's pretty much the only supported backend at this time. What other backend do you have in mind? pangoft2? Inkscape really should just use the cairo backend. Many cool new features (like vertical text support) are only implemented in the cairo backend.

OK, I was just trying to figure out what our options were. Of course Inkscape should be using the Cairo backend, we just don't at the moment.

The difficulty we're having is that not enough of Inkscape's rendering has been converted to Cairo for it to be easy for us to use Cairo's user-fonts for output. Do you think it would be possible for us to create a fake Cairo user-font which only has a partially-implemented render_glyph_func (returns the extents but doesn't draw anything) and then we figure it all out later and send it to our own renderer? I'm just looking for a more incremental approach to this feature rather than having to bundle in a complete Cairo conversion at the same time.

Changing the subject slightly, I can't see any mention of kerning in the current Cairo API. Is this something for later, or am I just ignoring things right in front of me again?

Richard.